I'd like to revisit the f2fs_gc flow and rewrite as follows.
1. In practical, the nGC parameter of f2fs_gc is meaningless. So, let's
remove it.
2. Background GC marks victim blocks as dirty one at a time.
3. Foreground GC should do cleaning job until acquiring enough free
sections. Afterwards, it needs to do checkpoint.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
---
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/gc.c | 60 +++++++++++++++++++------------------------------------
fs/f2fs/segment.c | 2 +-
3 files changed, 23 insertions(+), 41 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2807132..285e43d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -986,7 +986,7 @@ int do_write_data_page(struct page *);
int start_gc_thread(struct f2fs_sb_info *);
void stop_gc_thread(struct f2fs_sb_info *);
block_t start_bidx_of_node(unsigned int);
-int f2fs_gc(struct f2fs_sb_info *, int);
+int f2fs_gc(struct f2fs_sb_info *);
void build_gc_manager(struct f2fs_sb_info *);
int create_gc_caches(void);
void destroy_gc_caches(void);
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b0ec721..b4dd90c 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -78,7 +78,7 @@ static int gc_thread_func(void *data)
sbi->bg_gc++;
- if (f2fs_gc(sbi, 1) == GC_NONE)
+ if (f2fs_gc(sbi) == GC_NONE)
wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
else if (wait_ms == GC_THREAD_NOGC_SLEEP_TIME)
wait_ms = GC_THREAD_MAX_SLEEP_TIME;
@@ -651,62 +651,44 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
return ret;
}
-int f2fs_gc(struct f2fs_sb_info *sbi, int nGC)
+int f2fs_gc(struct f2fs_sb_info *sbi)
{
- unsigned int segno;
- int old_free_secs, cur_free_secs;
- int gc_status, nfree;
struct list_head ilist;
+ unsigned int segno, i;
int gc_type = BG_GC;
+ int gc_status = GC_NONE;
INIT_LIST_HEAD(&ilist);
gc_more:
- nfree = 0;
- gc_status = GC_NONE;
+ if (!(sbi->sb->s_flags & MS_ACTIVE))
+ goto stop;
if (has_not_enough_free_secs(sbi))
- old_free_secs = reserved_sections(sbi);
- else
- old_free_secs = free_sections(sbi);
-
- while (sbi->sb->s_flags & MS_ACTIVE) {
- int i;
- if (has_not_enough_free_secs(sbi))
- gc_type = FG_GC;
+ gc_type = FG_GC;
- cur_free_secs = free_sections(sbi) + nfree;
+ if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
+ goto stop;
- /* We got free space successfully. */
- if (nGC < cur_free_secs - old_free_secs)
- break;
-
- if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
+ for (i = 0; i < sbi->segs_per_sec; i++) {
+ /*
+ * do_garbage_collect will give us three gc_status:
+ * GC_ERROR, GC_DONE, and GC_BLOCKED.
+ * If GC is finished uncleanly, we have to return
+ * the victim to dirty segment list.
+ */
+ gc_status = do_garbage_collect(sbi, segno + i, &ilist, gc_type);
+ if (gc_status != GC_DONE)
break;
-
- for (i = 0; i < sbi->segs_per_sec; i++) {
- /*
- * do_garbage_collect will give us three gc_status:
- * GC_ERROR, GC_DONE, and GC_BLOCKED.
- * If GC is finished uncleanly, we have to return
- * the victim to dirty segment list.
- */
- gc_status = do_garbage_collect(sbi, segno + i,
- &ilist, gc_type);
- if (gc_status != GC_DONE)
- goto stop;
- nfree++;
- }
}
-stop:
- if (has_not_enough_free_secs(sbi) || gc_status == GC_BLOCKED) {
+ if (has_not_enough_free_secs(sbi)) {
write_checkpoint(sbi, (gc_status == GC_BLOCKED), false);
- if (nfree)
+ if (has_not_enough_free_secs(sbi))
goto gc_more;
}
+stop:
mutex_unlock(&sbi->gc_mutex);
put_gc_inode(&ilist);
- BUG_ON(!list_empty(&ilist));
return gc_status;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index de62409..4b00990 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -31,7 +31,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi)
*/
if (has_not_enough_free_secs(sbi)) {
mutex_lock(&sbi->gc_mutex);
- f2fs_gc(sbi, 1);
+ f2fs_gc(sbi);
}
}
--
1.8.0.1.250.gb7973fb
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